阅读说明：本技术 一种开关磁阻电机运行控制方法及系统 (Switched reluctance motor operation control method and system ) 是由 孙琍 于 2019-03-07 设计创作，主要内容包括：本发明涉及一种开关磁阻电机运行控制方法及系统,包括：控制装置以预设周期控制施加至多对线圈绕组上的导通电压,使每一对线圈绕组在预设周期的前半周期内被激励,在预设周期的后半周期内截止；以预设导通时间将导通电压施加至多对线圈绕组的第一线圈绕组,使第一线圈绕组被激励；在第一线圈绕组被激励期间的预定义节点,以预设导通时间将导通电压施加至沿转子的旋转方向且与第一线圈绕组相邻的第二线圈绕组,使第二线圈绕组被激励；控制施加在第一线圈绕组的导通电压和第二线圈绕组的导通电压,转子片从第一预设时间到第二预设时间的过程制动运行。解决开关磁阻电机启动及低速运行的问题,增加启动转矩并减小低速运行时的转矩脉动。(The invention relates to a method and a system for controlling the operation of a switched reluctance motor, comprising the following steps: the control device controls the conducting voltage applied to the coil windings in a preset period, so that each pair of coil windings is excited in the first half period of the preset period and is cut off in the second half period of the preset period; applying a turn-on voltage to a first coil winding of the plurality of coil windings for a preset turn-on time to energize the first coil winding; applying a turn-on voltage to a second coil winding adjacent to the first coil winding in a rotational direction of the rotor at a predetermined node during the first coil winding being excited for a preset turn-on time, causing the second coil winding to be excited; and controlling the conduction voltage applied to the first coil winding and the conduction voltage applied to the second coil winding, and braking the rotor sheet from a first preset time to a second preset time. The problems of starting and low-speed running of the switched reluctance motor are solved, the starting torque is increased, and the torque pulsation in the low-speed running is reduced.)

1. A switched reluctance motor operation control method, the switched reluctance motor comprising a rotor, a stator, and a control device electrically connected to the rotor and the stator, respectively, the rotor comprising a plurality of rotor pieces, the stator comprising a plurality of pairs of coil windings, each pair of coil windings forming one phase of the stator, and the number of the coil windings being greater than the number of the rotor pieces, characterized in that, when the motor is operating at a low speed, the control device controls a turn-on voltage applied to the plurality of pairs of coil windings at a preset period such that each pair of the coil windings is excited in a first half of the preset period and is turned off in a second half of the preset period; the method further comprises the following steps:

a control device applies a turn-on voltage to a first coil winding of the plurality of pairs of coil windings for a preset turn-on time to cause the first coil winding to be excited to move the rotor sheet toward the first coil winding;

a control device applies a turn-on voltage to a second coil winding adjacent to the first coil winding in a rotational direction of the rotor at a predetermined node during which the first coil winding is excited for the preset turn-on time, causing the second coil winding to be excited to accelerate movement of the rotor sheet during movement toward the first coil winding for a first preset time; the predefined node is a preset time node for controlling the conduction of the second coil winding;

the control device controls the conduction voltage applied to the first coil winding and the conduction voltage applied to the second coil winding to brake and run the rotor sheet from a first preset time to a second preset time; the sum of the first preset time and the second preset time forms the preset conduction time, the preset conduction time is the first half period of a preset period, and the first coil winding is any one pair of coil windings in the multiple pairs of coil windings.

2. The switched reluctance motor operation control method of claim 1, wherein the rotor sheet is aligned with the first coil winding when the control means applies the turn-on voltage to the first coil winding for a first preset time.

3. The switched reluctance motor operation control method of claim 1, wherein the predefined node for turning on the second coil winding is before the first preset time.

4. The operation control method of the switched reluctance motor according to claim 1, further comprising:

the control device controls the currents of the plurality of pairs of coil windings by adopting a stepping motor subdivision control method to obtain current curves of the plurality of pairs of coil windings.

5. The switched reluctance motor operation control method of claim 4, wherein the stepping motor subdivision-like control method is a current chopping method.

6. The switched reluctance motor operation control method of claim 4 or 5, wherein a current profile of each pair of the coil windings is a positive half cycle current profile of a sine wave shape.

7. The switched reluctance motor operation control method of claim 1, wherein phases of the first coil winding and the second coil winding overlap between the predefined node and the second preset time.

8. The switched reluctance motor operation control method of claim 1, wherein a position where the second coil winding is turned on is in a rotation direction of the rotor and is different from a position where the first coil winding is turned on by a preset electrical angle.

9. The switched reluctance motor operation control system of claim 1, the switched reluctance motor including a rotor, a stator, and a control device electrically connected to the rotor and the stator, respectively, the rotor including a plurality of rotor pieces, the stator including a plurality of pairs of coil windings, each pair of coil windings forming one phase of the stator, and the number of the coil windings being greater than the number of the rotor pieces, wherein the control device controls the turn-on voltages applied to the plurality of pairs of coil windings at a preset period such that each pair of the coil windings is energized in a first half period of the preset period and is turned off in a second half period of the preset period when the motor is operated at a low speed;

the control device is used for: applying a turn-on voltage to a first coil winding of the plurality of pairs of coil windings for a preset turn-on time to cause the first coil winding to be energized to move the rotor sheet toward the first coil winding;

applying, at a predefined node during the first coil winding being excited, a turn-on voltage to a second coil winding adjacent to the first coil winding in a rotational direction of the rotor for the preset turn-on time, causing the second coil winding to be excited so as to cause the rotor sheet to move with acceleration during movement toward the first coil winding for a first preset time; the predefined node is the preset time node for controlling the conduction of the second coil winding;

the control device is further configured to: controlling the conducting voltage applied to the first coil winding and the conducting voltage applied to the second coil winding to brake and run the rotor sheet from a first preset time to a second preset time;

the sum of the first preset time and the second preset time forms the preset conduction time, the preset conduction time is the first half period of a preset period, and the first coil winding is any one pair of coil windings in the multiple pairs of coil windings.

10. The switched reluctance machine operation control system of claim 9, wherein the rotor sheet is aligned with the first coil winding when the control means applies the turn-on voltage to the first coil winding for a first preset time.

Technical Field

The invention relates to the field of motor control, in particular to a method and a system for controlling the operation of a switched reluctance motor.

Background

The switched reluctance motor is a novel speed regulating motor, the speed regulating system has the advantages of a direct current speed regulating system and an alternating current speed regulating system, and the switched reluctance motor is a latest generation stepless speed regulating system of a frequency conversion speed regulating system and a brushless direct current motor speed regulating system. The speed regulating device has the advantages of simple and firm structure, wide speed regulating range, excellent speed regulating performance, higher efficiency in the whole speed regulating range and high system reliability. The device mainly comprises a switched reluctance motor, a power converter, a controller and a position detector. The controller contains a power converter and control circuitry, and a rotor position detector is mounted at one end of the motor.

Nowadays, the application and development of the switched reluctance motor have made remarkable progress, and the switched reluctance motor has been successfully applied to various fields such as electric vehicle driving, general industry, household appliances and textile machinery, and the like, the power range is from 10W to 5MW, and the maximum speed is as high as 100,000 r/min.

However, in the conventional switched reluctance motor, since only two photoelectric switches are used for detecting the position of the rotor, it is difficult to control the operation of the low-speed section during the low-speed operation. In addition, different from the medium-high speed operation, in order to maintain a low rotating speed, in the low-speed section operation control, the voltage on the motor winding needs to be reduced to be low enough, the torque of the motor is insufficient, the motor can be stopped by slight touch, and the low-speed operation performance of the motor is greatly influenced. Therefore, a method for effectively solving the problem of low-speed operation of the switched reluctance motor is urgently needed to be found.

Disclosure of Invention

The present invention provides a method and a system for controlling operation of a switched reluctance motor, aiming at the above-mentioned defects in the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows: there is provided an operation control method of a switched reluctance motor including a rotor, a stator, and a control device electrically connected to the rotor and the stator, respectively, the rotor including a plurality of rotor pieces, the stator including a plurality of pairs of coil windings, each pair of coil windings forming one phase of the stator, and the number of the coil windings being greater than the number of the rotor pieces, the control device controlling turn-on voltages applied to the plurality of pairs of coil windings at a preset period such that each pair of the coil windings is excited in a first half of the preset period and turned off in a second half of the preset period when the motor is operated at a low speed; the method further comprises the following steps:

a control device applies a turn-on voltage to a first coil winding of the plurality of pairs of coil windings for a preset turn-on time to cause the first coil winding to be excited to move the rotor sheet toward the first coil winding;

a control device applies a turn-on voltage to a second coil winding adjacent to the first coil winding in a rotational direction of the rotor at a predetermined node during which the first coil winding is excited for the preset turn-on time, causing the second coil winding to be excited to accelerate movement of the rotor sheet during movement toward the first coil winding for a first preset time; the predefined node is a preset time node for controlling the conduction of the second coil winding;

the control device controls the conduction voltage applied to the first coil winding and the conduction voltage applied to the second coil winding to brake and run the rotor sheet from a first preset time to a second preset time; the sum of the first preset time and the second preset time forms the preset conduction time, the preset conduction time is the first half period of a preset period, and the first coil winding is any one pair of coil windings in the multiple pairs of coil windings.

Preferably, the control means applies a turn-on voltage to the first coil winding for a first preset time, and the rotor sheet is aligned with the first coil winding.

Preferably, the predefined node for switching on the second coil winding is before the first preset time.

Preferably, the method further comprises the following steps:

the control device controls the currents of the plurality of pairs of coil windings by adopting a stepping motor subdivision control method to obtain current curves of the plurality of pairs of coil windings.

Preferably, the stepping motor subdivision control method is a current chopping method.

Preferably, the current curve of each pair of the coil windings is a positive half-cycle current curve of a sine wave shape.

Preferably, the phases of the first coil winding and the second coil winding overlap between the predefined node and the second preset time.

Preferably, a position where the second coil winding is turned on is in a rotation direction of the rotor, and is different from a position where the first coil winding is turned on by a preset electrical angle.

The invention also provides a switched reluctance motor operation control system, which comprises a rotor, a stator and a control device electrically connected with the rotor and the stator respectively, wherein the rotor comprises a plurality of rotor sheets, the stator comprises a plurality of pairs of coil windings, each pair of coil windings forms one phase of the stator, the number of the coil windings is larger than that of the rotor sheets, and when the motor operates at a low speed, the control device controls the conducting voltage applied to the plurality of pairs of coil windings in a preset period, so that each pair of coil windings is excited in the first half period of the preset period and is cut off in the second half period of the preset period;

the control device is used for: applying a turn-on voltage to a first coil winding of the plurality of pairs of coil windings for a preset turn-on time to cause the first coil winding to be energized to move the rotor sheet toward the first coil winding;

applying, at a predefined node during the first coil winding being excited, a turn-on voltage to a second coil winding adjacent to the first coil winding in a rotational direction of the rotor for the preset turn-on time, causing the second coil winding to be excited so as to cause the rotor sheet to move with acceleration during movement toward the first coil winding for a first preset time; the predefined node is the preset time node for controlling the conduction of the second coil winding;

the control device is further configured to: controlling the conducting voltage applied to the first coil winding and the conducting voltage applied to the second coil winding to brake and run the rotor sheet from a first preset time to a second preset time;

the sum of the first preset time and the second preset time forms the preset conduction time, the preset conduction time is the first half period of a preset period, and the first coil winding is any one pair of coil windings in the multiple pairs of coil windings.

Preferably, the control means applies a turn-on voltage to the first coil winding for a first preset time, and the rotor sheet is aligned with the first coil winding.

The implementation of the operation control method of the switched reluctance motor has the following beneficial effects: the control device controls the conducting voltage applied to the coil windings in a preset period when the switched reluctance motor is started and runs at a low speed, so that each pair of coil windings is excited in the first half period of the preset period, the coil windings are cut off in the second half period of the preset period, the period is fixed, and simultaneously 2 phases are switched on, and the current on each phase is in a sine first half-cycle waveform in a current chopping mode, thereby effectively solving the problem that the existing switched reluctance motor is difficult to control in the low-speed running process, not only realizing the dead-zone-free starting of the switched reluctance motor, but also reducing the torque pulsation problem during the low-speed running and improving the performance of the motor during the starting and the low-speed running.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

fig. 1 is a schematic flowchart of a method for controlling operation of a switched reluctance motor according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a switched reluctance motor according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of phase voltage drive waveforms provided by an embodiment of the present invention;

fig. 4 is a schematic diagram of phase current waveforms provided by an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, an embodiment of the present invention provides a method for controlling operation of a switched reluctance motor, where the method for controlling operation of a switched reluctance motor effectively completes control of the switched reluctance motor during start and low-speed operation by combining two-phase operation with current chopping control on a timing axis similar to subdivision control of a stepping motor.

The operation control method of the switched reluctance motor provided by the embodiment of the invention can be applied to the switched reluctance motor to control the starting and low-speed operation of the switched reluctance motor. In an embodiment of the present invention, a switched reluctance motor includes: the rotor comprises a plurality of rotor sheets, the stator comprises a plurality of pairs of coil windings, each pair of coil windings forms one phase of the stator, and the number of the coil windings is more than that of the rotor sheets.

In the switched reluctance motor operation control method according to the embodiment of the present invention, when the switched reluctance motor is started and operates at a low speed, the control device controls the conduction voltage applied to the plurality of pairs of coil windings in a preset period, so that each pair of coil windings is excited in the first half of the preset period and is turned off in the second half of the preset period, and the control device controls the conduction voltage and the current of the coil windings in the preset period, respectively, thereby controlling the switched reluctance motor to operate on a fixed time axis.

Further, as shown in fig. 1, the method comprises the steps of: step S101, step S102, and step S103.

Specifically, in step S101, the control device applies a turn-on voltage to a first coil winding of the plurality of pairs of coil windings for a preset turn-on time, so that the first coil winding is excited to move the rotor sheet toward the first coil winding.

In the embodiment of the present invention, the first coil winding is any one of a plurality of pairs of coil windings. It is to be understood that the first coil winding may be a first pair of coil windings that are energized when the switched reluctance motor is turned on, or may be a coil winding that is energized at any one time when the switched reluctance motor is started or operates at a low speed. The preset conduction time is the first half period of the preset period.

When the first coil winding is excited, a corresponding excitation effect is generated, and at the moment, the rotor sheet closest to the first coil winding moves towards the first coil winding due to the excitation effect of the first coil winding, so that the rotor sheet is driven to move towards the first coil winding.

Step S102, the control device applies a turn-on voltage to a second coil winding adjacent to the first coil winding in the rotation direction of the rotor for a preset turn-on time at a predefined node during which the first coil winding is excited, so that the second coil winding is excited, so that the rotor sheet is moved with acceleration during the movement toward the first coil winding for the first preset time.

In the embodiment of the invention, the predefined node is a preset time node for controlling the conduction of the second coil winding.

Optionally, in an embodiment of the present invention, the predefined node for turning on the second coil winding is before the first preset time. Further, the first preset time is less than the preset on-time.

In the embodiment of the invention, when the predefined node is reached, the control device controls the output of the conduction voltage to the second coil winding according to the preset conduction time, so that the second coil winding is excited at the predefined node, namely the second coil winding has the driving voltage, at the moment, the second coil winding is conducted, further, the conduction position of the second coil winding is in the rotation direction of the rotor (namely the moving direction of the rotor), and the difference between the position for switching on the second coil winding and the position for switching on the first coil winding is a preset electrical angle. Wherein, the preset electrical angle satisfies the following conditions:

the preset electrical angle is 360 °/(M/2).

M denotes the number of coil windings, that is, the stator of the switched reluctance motor according to the embodiment of the present invention includes M/2 pairs of coil windings, each pair of coil windings being one phase of the switched reluctance motor.

S103, controlling the conduction voltage applied to the first coil winding and the conduction voltage applied to the second coil winding by the control device to brake and run the rotor sheet from the first preset time to the second preset time; the sum of the first preset time and the second preset time forms a preset conduction time which is the first half period of the preset period.

Further, in the embodiment of the present invention, the control device applies the turn-on voltage to the first coil winding, and when the first preset time is reached, the rotor sheet which moves toward the first coil winding and is closest to the first coil winding is aligned with the first coil winding.

To illustrate by a specific example, as shown in fig. 2, the stator includes 4 pairs of coil windings, respectively, an a-phase coil winding, a B-phase coil winding, a C-phase coil winding, and a D-phase coil winding, which are 4-phase coil windings, wherein each phase coil winding includes two coil windings (as shown in fig. 2, the a-phase coil winding includes an a1 coil winding and an a2 coil winding, the B-phase coil winding includes a B1 coil winding and a B2 coil winding, the C-phase coil winding includes a C1 coil winding and a C2 coil winding, and the D-phase coil winding includes a D1 coil winding and a D2 coil winding), and the two coils of each phase are connected in series. As shown in fig. 2, the rotor includes 6 rotor sheets, i.e., a rotor sheet, b rotor sheet, c rotor sheet, d rotor sheet, e rotor sheet, and f rotor sheet, for a total of 6 rotor sheets.

As shown in fig. 2, it is assumed that at the time of starting the switched reluctance motor, i.e., at the time of T0, the coil winding of phase a is energized, i.e., the coil windings of phase a1 and a2 in series receive the turn-on voltage, at this time, the coil windings of phase a1 and a2 are turned on, and the a rotor piece closest to the coil winding of phase a1 moves toward the coil winding of phase a1 in the shortest path due to the excitation of the coil winding of phase a1, while the d rotor piece moves toward the coil winding of phase a2 in the shortest path due to the excitation of the coil winding of phase a 2.

Further, when the predefined node is reached, the control device applies the turn-on voltage to the second coil winding along the rotation direction of the rotor and believed to the first coil winding for a preset turn-on time, so that the second coil winding is excited to be excitedThe rotor sheet is accelerated during the movement toward the first coil winding for a first preset time. That is, as shown in FIG. 2, when a predefined node is reached, set to T_{Preparation of}The coil winding of the B1 and the coil winding of the B2 are excited, the coil winding of the B1 and the coil winding of the B2 are conducted, the a rotor piece and the d rotor piece respectively move towards the coil winding of the A1 and the coil winding of the A2 and are attracted by excitation of the coil winding of the A1 and the coil winding of the A2, the coil winding of the B1 and the coil winding of the B2 are conducted while the coil winding of the A1 and the coil winding of the A2 are conducted, excitation attraction effect on the rotor piece a and the rotor piece d in the rotation direction of the rotor is generated simultaneously, the moving speed and torque during starting or low-speed operation can be increased, and the speed and the torque of the rotor during the first preset time are increased.

When the first preset time is reached, the a rotor plate is aligned with the a1 coil winding, while the d rotor plate is aligned with the a2 coil winding. In the embodiment of the invention, the phase-A coil winding and the phase-B coil winding are both in a conducting state in a time period from a first preset time to a second preset time, however, at this time, the phase-A rotor sheet continues to move towards the phase-B1 coil winding, the phase-d rotor sheet continues to move towards the phase-B2 coil winding, and due to the excitation of the phase-A1 coil winding and the phase-A2 coil winding, the rotor forms a braking operation, namely, during the period from the first preset time to the second preset time, the rotor is in a braking operation process (equivalent to a braking process) until the second preset time is reached, the phase-A coil winding performs a latter half cycle, at this time, the phase-A coil winding is not input with conducting voltage, the phase-A coil winding is cut off, and the phase-A rotor sheet and the phase-d rotor sheet respectively accelerate towards the phase-B1 coil winding. Therefore, in the first half period of the preset period of the phase-A coil winding, the rotor is in an accelerated moving process, and in the process from the predefined node to the first preset time, the speed of the rotor in accelerated moving is further improved due to the conduction effect of the phase-B coil winding; during the process from the first preset time to the second preset time, the rotor is in a braking movement process, so that the rotor forms an accelerating movement process and a braking movement process in the former half period of any pair of coil windings, namely, during the low-speed operation process of the switched reluctance motor, the switched reluctance motor comprises an alternate accelerating process and a braking process.

Further, as shown in fig. 3, a-phase coil winding, a B-phase coil winding, a C-phase coil winding, and a D-phase coil winding are illustrated, and for convenience of description, the phases are explained below, that is, fig. 3 illustrates voltage driving waveforms of a-phase, B-phase, C-phase, and D-phase of the switched reluctance motor.

As shown in fig. 3, at T₀To T₂Phase A is on at time T₀To T_{Preparation of}Phase A is an acceleration moving process at T₁To T₂Phase A is the braking movement process and at T_{Preparation of}To T₂When the phase A and the phase B are the same, conducting is carried out, and so on, as shown in figure 3, any adjacent phase of the switched reluctance motor is at T₀To T₂Is in an on state at a time, and is at T₀To T_{Preparation of}At time T, the moving process is accelerated₁To T₂At the moment of braking movement and at T_{Preparation of}To T₂At the moment, two adjacent phases are conducted simultaneously.

For ease of description, the following description will be made with a single coil winding, since the a rotor piece is moved toward the a1 coil and not aligned with the a1 coil, since the a1 coil and the B1 coil are at T_{Preparation of}To T₂The rotor sheet a is switched on at the same time, so that the rotor sheet a does not oscillate when moving to be aligned towards the coil A1, and after the rotor sheet a is aligned with the coil A1, the rotor sheet a does not oscillate back and forth under the action of the coil winding B1, so that the oscillation phenomenon of the rotor oscillating back and forth is avoided; by analogy, when any rotor sheet moves towards the adjacent stator, the oscillation phenomenon of back-and-forth swing cannot be generated. Therefore, the switched reluctance motor adopting the method does not generate the oscillation phenomenon of the back-and-forth swing of the rotor in the low-speed operation process, and ensures the low-speed operation of the switched reluctance motor.

Further, the operation control method of the switched reluctance motor according to the embodiment of the present invention further includes:

the control device controls the current of each phase of coil winding by adopting a subdivision control method similar to a stepping motor so as to obtain current curves of a plurality of pairs of coil windings.

In the embodiment of the invention, the subdivision control method similar to the stepping motor is a current chopping method. The current profile for each pair of coil windings is the positive half cycle current profile of a sinusoidal waveform, as shown in fig. 4. The current chopping method on the timing shaft similar to the subdivision control of the stepping motor is adopted for control, so that the current on each phase is in a sine upper half-cycle waveform, the fluctuation of the bus current is reduced, the synthesized torque value is large and stable, the torque pulsation of the switched reluctance motor during low-speed running is reduced, no dead zone starting of the switched reluctance motor can be realized, and the torque is increased.

Further, as can be seen from fig. 3, between the predefined node and the second preset time, the first coil winding and the second coil winding are simultaneously turned on, and thus, phases of the first coil winding and the second coil winding overlap.

The invention also discloses a switched reluctance motor operation control system which can be used for realizing the switched reluctance motor operation control method.

In the embodiment of the invention, the switched reluctance motor in the switched reluctance motor operation control system comprises a rotor, a stator and a control device which is respectively electrically connected with the rotor and the stator, wherein the rotor comprises a plurality of rotor sheets, the stator comprises a plurality of pairs of coil windings, each pair of coil windings forms one phase of the stator, and the number of the coil windings is greater than that of the rotor sheets, when the motor operates at a low speed, the control device controls the conducting voltage applied to the plurality of pairs of coil windings in a preset period, so that each pair of coil windings is excited in the first half period of the preset period and is cut off in the second half period of the preset period.

In the switched reluctance motor operation control system according to the embodiment of the present invention, when the switched reluctance motor operates at a low speed, the control device controls the conduction voltages applied to the plurality of pairs of coil windings at a preset period, so that each pair of coil windings is excited in the first half of the preset period and is turned off in the second half of the preset period, and the control device controls the conduction voltages of the coil windings at the preset period, respectively, thereby controlling the switched reluctance motor to operate on a fixed time axis.

The control device is used for: applying a turn-on voltage to a first coil winding of the plurality of pairs of coil windings for a preset turn-on time to cause the first coil winding to be energized to move the rotor sheet toward the first coil winding; applying, at a predefined node during which the first coil winding is excited, a turn-on voltage to a second coil winding adjacent to the first coil winding in a rotational direction of the rotor for a preset turn-on time, causing the second coil winding to be excited so as to cause accelerated movement of the rotor sheet during movement toward the first coil winding for a first preset time; in the embodiment of the invention, the predefined node is a preset time node for controlling the conduction of the second coil winding. When the first coil winding is excited, a corresponding excitation effect is generated, and at the moment, the rotor sheet closest to the first coil winding moves towards the first coil winding due to the excitation effect of the first coil winding, so that the rotor sheet is driven to move towards the first coil winding.

Optionally, in an embodiment of the present invention, the predefined node for turning on the second coil winding is before the first preset time. Further, the first preset time is less than the preset on-time.

In the embodiment of the invention, when the predefined node is reached, the control device controls the output of the conduction voltage to the second coil winding according to the preset conduction time, so that the second coil winding is excited at the predefined node, namely the second coil winding has the driving voltage, at the moment, the second coil winding is conducted, further, the conduction position of the second coil winding is in the rotation direction of the rotor (namely the moving direction of the rotor), and the difference between the position for switching on the second coil winding and the position for switching on the first coil winding is a preset electrical angle. Wherein, the preset electrical angle satisfies the following conditions:

the preset electrical angle is 360 °/(M/2).

M denotes the number of coil windings, that is, the stator of the switched reluctance motor according to the embodiment of the present invention includes M/2 pairs of coil windings, each pair of coil windings being one phase of the switched reluctance motor.

The control device is further configured to: controlling the conduction voltage applied to the first coil winding and the conduction voltage applied to the second coil winding to brake the rotor sheet to run from the first preset time to the second preset time; the sum of the first preset time and the second preset time forms preset conduction time which is the first half period of the preset period, and the first coil winding is any one of the multiple pairs of coil windings.

Further, the control device applies the turn-on voltage to the first coil winding for a first preset time, and the rotor sheet is aligned with the first coil winding.

Optionally, the control device in the embodiment of the present invention controls currents of a plurality of pairs of coil windings by using a stepping motor subdivision control method, so as to obtain a current curve of each phase of coil winding. The subdivision control method similar to the stepping motor is a current chopping method. The current curve of each pair of coil windings is a positive half cycle current curve of a sine wave shape. The current chopping method on the timing shaft similar to the subdivision control of the stepping motor is adopted for control, so that the current on each phase is in a sine upper half-cycle waveform, the fluctuation of the bus current is reduced, the synthesized torque value is large and stable, the torque pulsation of the switched reluctance motor during low-speed running is reduced, no dead zone starting of the switched reluctance motor can be realized, and the torque is increased.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the claims of the present invention.

It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.